Security key generation and management method of PDCP distributed structure for supporting dual connectivity

Abstract

The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A method for communicating by a user equipment with a macro cell base station and a small cell base station in a communication system is provided. The method comprises applying a first base station security key to a first communication link with the macro cell base station; generating a second base station security key to be used for a second communication link with the small cell base station based on the first base station security key; applying the second base station security key to the second communication link with the small cell base station; and communicating through at least one of the first communication link and the second communication link.

What is claimed is: 
     
       1. A method for communicating by a user equipment (UE) in a communication system, the method comprising:
 receiving, from a first base station, a counter for a second base station; 
 generating a second security key for a second radio bearer associated with the second base station based on the counter; and 
 applying the second security key to the second radio bearer associated with the second base station. 
 
     
     
       2. The method of  claim 1 , wherein the second security key for the second radio bearer associated with the second base station is generated based on the counter and a first security key for a first radio bearer associated with the first base station. 
     
     
       3. The method of  claim 2 ,
 wherein the first security key is applied to the first radio bearer associated with the first base station, and 
 wherein the second security key is different from the first security key. 
 
     
     
       4. The method of  claim 1 , wherein the counter is received through a radio resource control (RRC) connection reconfiguration message. 
     
     
       5. The method of  claim 1 , further comprising:
 receiving, from the first base station, a new counter in a case that another base station is newly added; and 
 generating a new security key for another radio bearer associated with the newly added base station based on the new counter. 
 
     
     
       6. The method of  claim 5 , further comprising:
 deleting the new security key in a case that the radio bearer associated with the newly added base station is released. 
 
     
     
       7. A user equipment (UE) communicating in a communication system, the UE comprising:
 a transceiver; and 
 a controller configured to:
 receive, from a first base station via the transceiver, a counter for a second base station; 
 generate a second security key for a second radio bearer associated with the second base station based on the counter; and 
 apply the second security key to the second radio bearer associated with the second base station. 
 
 
     
     
       8. The UE of  claim 7 , wherein the second security key for the second radio bearer associated with the second base station is generated based on the counter and a first security key for a first radio bearer associated with the first base station. 
     
     
       9. The UE of  claim 8 ,
 wherein the first security key is applied to the first radio bearer associated with the first base station, and 
 wherein the second security key is different from the first security key. 
 
     
     
       10. The UE of  claim 7 , wherein the counter is received through a radio resource control (RRC) connection reconfiguration message. 
     
     
       11. The UE of  claim 7 , wherein the controller is further configured to:
 receive, from the first base station via the transceiver, a new counter in a case that another base station is newly added; and 
 generate a new security key for another radio bearer associated with the newly added base station based on the new counter. 
 
     
     
       12. The UE of  claim 11 , wherein the controller is further configured to delete the new security key in a case that the radio bearer associated with the newly added base station is released. 
     
     
       13. A non-transitory storage medium having stored therein instructions which cause, when executed by at least one processor, the at least one processor to perform at least one operation which comprises:
 receiving, from a first base station, a counter for a second base station; 
 generating a second security key for a second radio bearer associated with the second base station based on the counter; and 
 applying the second security key to the second radio bearer associated with the second base station. 
 
     
     
       14. The non-transitory storage medium of  claim 13 , wherein the second security key for the second radio bearer associated with the second base station is generated based on the counter and a first security key for a first radio bearer associated with the first base station. 
     
     
       15. The non-transitory storage medium of  claim 14 ,
 wherein the first security key is applied to the first radio bearer associated with the first base station, and 
 wherein the second security key is different from the first security key. 
 
     
     
       16. The non-transitory storage medium of  claim 13 , wherein the counter is received through a radio resource control (RRC) connection reconfiguration message. 
     
     
       17. The non-transitory storage medium of  claim 13 , wherein the at least one operation further comprises:
 receiving, from the first base station, a new counter in a case that another second base station is newly added; and 
 generating a new second security key for another radio bearer associated with the newly added second base station based on the new counter. 
 
     
     
       18. The non-transitory storage medium of  claim 17 , wherein the at least one operation further comprises:
 deleting the new security key in a case that the radio bearer associated with the newly added base station is released.